Rayon spinning apparatus



May 2, 1939. H. E. KLINE I RAYON SPINNING APPARATUS Filed Oct. 5, 1935 I I l 5W ll .w 1

INVENTOR HAYDEN B. Ku/vE Patented May 2, 1939 U NITED- STATES PATENT OFFICE Industrial Rayon Corporation, a corporation of Delaware Cleveland; Ohio,

Application October 5, 1935; Serial:No. 43,727

3 Claims.

This invention relates to rayon spinning apparatusr Heretofore in the manufacture of rayon it has been customary to incorporate in the spinning apparatus, ordinarily. in intimate association with the pump, a pressure bottle the function which has been to reduce the efiect of pulsations introduced by the pump. This pressure bottle has generally been mounted on the pump itself in such relation to the discharge thereof that pulsations have to a greater or lessextent been cushionedby means of a body of air entrapped within the pressure bottle. Various difficulties have attended the use of such pressure bottles, them the fact that rayon mass, especially viscose, bysettingup within the pressure bottle soon impairs itsfunctioning; the fact that such bottles. being of glass, are easilyv broken; and the fact that extensive cleaning and other conditioning is necessary after relativelyshort periods of use: More recently it has been proposed in Patent No. 1,958,009 to'McKee, granted -May-8, 193d, to employ, in lieu of the pressure bottle,-a pulsation eliminator; comprising a non-rigid vessel which rayon mass continuously :flows, such vesseibeing located at some convenient point in the line between the pump-and. the-spinneret. This patent discloses the use, among 'otherthings, oia thin-walledmetal tube formed into a coil or helix adapted, by expansion of the tube, to cushion pulsations. While such an arrangement is wholly operative that it largely or entirely eliminates pulsations from the rayonzspinning apparatus with which it is associated, it is not always possible to use the same in view of the fact that existing rayon spinning machines are in general well adapted to accommodate such devices The principle of operation thereininvolved...is, .however, undeubtedly entirely. sound.

It an object of the present invention, em

nloying the principlelof this patentto "provide a practicable meansior reducingthe efiect-of pul sations, such means being adapted tobe interposed in the relatively'ilimit'ed amount or room available between the pumpor, more accuratelyv the pump bracket and the apronlwlochcandl filter or other trough fitting, to one or bothoi which such means-must in practice be directly connected. A furtheraobjectanf the-.inventhm to provide a short, straight, upwardly-exten normally collapsed, thin-walled metal expan on tube capable-of cushioning the effect of the 1 sations introduced by the'pump. sun a in than objectrof the invention is to provide means f this type adapted to be employed in existing rung machines without the necessity of making extensiveichanges. 'Otherobjects and advantages of the invention will in part be obvious and will in part appearmore in' detailhereinafter as the 7 description oi'the invention proceeds. 1 i

For illustrative purposes, the invention will be shown-and described as applied to rayon spinningapparatus employed 'in the manufacture of multiplefilament viscose rayon; more particularly, to such apparatus in which is employed a 10 positive displacement pump as, for example, piston pumpof'the type-usually used. It is obvious-that the inventionis equally applicable to other methods of manufacturing rayon as, for example, the cuprammonium, cellulose acetateand 1 nitrocellulose processes. It will be understood that while for convenience reference is made herein.to rayon-manufacture, the fact of the matter that the invention is equally applicable to'the manufacture of other artificial materials 9 similarly produced as,- for example, artificial horsehair, staple fiber, artificial straw, bands, ribb-om and the like:

the-accompanying drawing, in which like reierencecharactersrefer to like parts throughout,- Figure 1 .representsa. front elevation of rayon spinning apparatus employing the instant invention, parts. beingcshown as broken away for simplicity iniliustitation. Figure 2 shows a correspending side elevation with parts in section. 30 Figures Band 4- show in section in somewhat greater detail thethin walled metal tube employedin the. rayon spinning apparatus of Figures .1 and 2, theiiorme-r showingthe tube viewed from the direction from which it is seen in Figure 35 1 and the latter showing it viewed from the direction iromiwhich-it is seen in Figure 2. Figure 5 isa cross section on theline 5-5 of Figure 3... Figure-fiisan end-:zelevationoi the same tube.

Reierringmwto Figures land 2, pipe line l supplies viscose to the pump-2 through side 3a of pump bracket Directly'connected at one end thereoLtothe-pump bracket 3 and at the other end thereof itothe apron block .5is the expansion tube 4. Aszmore clearly shown in Figure 2, apron 5 block 5 is mounted on trough apron 6, which is in turn meuntedon; trough 1 containing coagulating baths; Proiectingrdownward into the latter is mass tube 9- *carrying-scandle filter It in close proximity to the point of its connection to apron biockii. Disposed :at the outer end of mass tube Sis spinneret l L The flow of rayon mass is from pipeline I through :one side, 3a., of pump bracket 3th pumpi, thence through the other side, 3b, of pump bracket to expansion tube 4, from which spinneret ll.

Pump 2 is a conventional positive displacement pump of the piston type. The pressure bottle commonly employed on pumps. of this kind is absent, its function being performed pursuant to the teachings of the invention by means of expansion tube l from which rayon mass is piped from the pump bracket 3 to the apron block 5. Expansion tube 3 is generally similar to the cylindrical tube previously employed in apparatus using, in addition thereto, a pressure bottle; but differs therefrom in that it is deformed from the cylindrical so as to be normally collapsed, its normally collapsed shape, shown to best advantage in Figures l, 3 and 5, permitting it to expand slightly to assume under the influence of pulsations in the rayon mass a somewhat more nearly cylindrical shape. The expansion tube d is connected to the pump bracket 3 and the apron block 5 in exactly the same way as cylindrical tubes of the type previously employed in conjunction with pressure bottles.

As shown in Figures 3 and 4, the tube i is deformed from the cylindrical to such an extent that in cross section it has the appearance shown in Figure 5. It is preferably made of thin-walled seamless steel tubing approximately 0.004 inch in thickness and three-eighths of an inch in original outer diameter; i. e., before being deformed to the shape shown. In order to reinforce it at its ends, where it is connected respectively to pump bracket 3 and apron block 5, it is provided at each end with a hollow cylindrical plug 52 having tapered portion l3, such plug l2 being fitted into the tube 3 by a press fit. Such plugs l 2 may be of a length in the neighborhood of one or one and one-quarter inches and may conveniently have a bore one-quarter of an inch in diameter. The tubes l will be as long as necessary, as, for example, in a typical case some eight to ten inches.

The apron block 5 represents only one type of trough fitting that may be employed, since various trough fittings are available and can be used in the practice of the invention in much the same way as the apron block 5. As most clearly appears from Figures 1 and 2, the apron block 5 has a threaded portion H5 extending downward through the trough apron 6 into which threaded portion it projects one end of the expansion tube a. The apron block 5 is clamped to the trough apron 6 by means of a washer l5 and threaded nut 6. The expansion tube connecting the pump bracket 3 and the apron block 5 is held rigidly in place at its upper end by means of washers Ill and a nut l8 serving to clamp the same into tight relation to the tube. At its other end, the expansion tube t is held in place in the pump bracket 3 by conventional means; to wit, washers it) and nut 25.

In operation, the pump 2 is driven by the shaft 2! shown in Figures 1 and 2, which operates the pistons of the pump and thereby introduces the pulsation eifect above referred to. These pulsations tend to appear in the rayon extruded from the spinneret l l unless some provision is made for their cushioning, which in this instance takes the form of the expansion tube 4. The pressure of the rayon, mass under the influence of the pulsations causes the expansion tube i to expand slightly, providing the desired cushioning effect. The rayon mass is then transmitted in the usual manner to the apron block 5, through the candle filter l5, and thence by means of mass tube 9 and -it flows in turn to apron block 5, mass tube 9 and the spinneret I l to the coagulating bath 8, wherein it assumes the form of thread. Experiments have shown that an expansion tube of this type is capable of cushioning pulsations to an extent at least as great as that previously provided by the pressure bottle. The expansion tube 4 replaces the tube, round in cross section, commonly used hereto-fore in conjunction with a pressure bottle mounted directly on the pump: it does not, therefore, introduce an additional element, but instead makes possible the elimination of the pressure bottle without elimination of its function.

It is obvious that numerous changes may be made without departing from the spirit of the invention. Thus the expansion tube of the invention may be made longer or shorter than that illustrated and may be fitted by different means on the one hand to the pump or, more accurately, the pump bracket and on the other to the trough fitting as, for example, the apron block shown and described. The cross section may have a different normal shape, as, for example, a triangular shape, rather than the somewhat fiat shape shown in Figure 5. Obviously, the tube may be disposed so that it is mounted to extend at a substantial angle to the vertical rather than generally upward or vertically in the manner shown. It may, of course, be made of any material that over a prolonged period of time will stand up under the effect of the pulsations introduced by the pump. For this purpose, a thin-walled, seamless tube of high grade steel, preferably hardened and tempered after being deformed to the desired shape, is preferred.

It will be understood that while in the embodiment herein shown and described a candle filter is employed in addition to the apron block, one or the other of these may, if desired, be omitted. Where the apron block is omitted, the candle filter is ordinarily permitted to rest directly on the trough apron or trough wall; so that it serves to some extent the same functions as the apron block, particularly in lending rigidity to the organization. In such case, the expansion tube of the invention may be connected at one end to the candle filter. As herein used, the term trough fitting is intended to include any element, such as a candle filter, that takes the place of the apron block, regardless of whether the mass tube and associated apparatus is disposed to pivot about such trough fitting, as in the'embodiment of the invention herein shown and described, or, as is sometimes the case, about the pump bracket.

It is intended that the patent shall cover, by suitable expression in the appended claims, whatever features of patentable novelty reside in the invention.

What I claim is:

1. In rayon spinning apparatus including a positive displacement pump and a trough fitting, a pressure responsive element operating to minimize pulsations resulting from the use of the positive displacement pump comprising a short, straight, open-ended, internally unobstructed metal tube having thin, flexible walls of a length sufiicient to permit the tube to serve as a direct connection between the pump and the trough fitting, said tube being normally collapsed along a portion of its length but being capable, under the influence of pulsations from the pump, of expanding against the pressure of the atmosphere to minimize the effect of said pulsations before they are transmitted beyond the trough fitting.

2. In rayon spinning apparatus including a positive displacement pump and a trough fitting,

a pressure responsive element operating to minimize pulsations resulting from the use of the positive displacement pump comprising a short, straight, open-ended, internally unobstructed metal tube having thin, flexible walls of a length sufficient to permit the tube to serve as a direct connection between the pump and the trough fitting, said tube being normally collapsed along a portion of its length but being capable, under the influence of pulsations from the pump, of expanding against the pressure of the atmosphere to minimize the effect of said pulsations before they are transmitted beyond the trough fitting and, at at least one end thereof, reinforcing means conforming to the shape of the end of said tube.

3. In rayon spinning apparatus including a positive displacement pump and a trough fitting,

a pressure responsive element operating to minimize pulsations resulting from the use of the positive displacement pump comprising a short, straight, open-ended, internally unobstructed metal tube having thin, flexible walls of a length sufficient to permit the tube to serve as a direct connection between the pump and the trough fitting, said tube being normally collapsed along a portion of its length but being capable, under the influence of pulsations from the pump, of expanding against the pressure of the atmosphere to minimize the effect of said pulsations before they are transmitted beyond the trough fitting and, at each end thereof, internal reinforcing means conforming to the shape of the end of said tube.

HAYDEN B. KLINE. 

